I didn't experience this with my RRF Engineer. Are they not showing up in the Powers window (Default keybind 'P'), or did they just not appear on your power tray? I have had powers not added to the tray, so they might be in the Powers Window if you haven't looked yet.
This fixed itself after I spent more points on my character skills. It seems the abilities were not granted to me because I hadn't spent enough points in skills for that rank level. As soon as I spent enough skill points I received the abilities automagically.